Rationale: Pediatric anxiety disorders are highly prevalent and associated with adverse long-term consequences. These disorders are believed to be influenced by underlying cognitive and neural mechanisms which are not well understood. Recent studies suggest specific neurocognitive models associated with adult anxiety disorders;such data in young individuals are scant. Purpose: To develop expertise in the study of neurocognitive mechanisms in pediatric anxiety disorders using functional magnetic resonance imaging (fMRI). Initial studies focus on adolescents with generalized anxiety disorder (GAD). Long-term plans are to become an independent investigator and extend research to other pediatric anxiety disorders. Training Plan: The candidate will receive training in: 1) developmental and diagnostic issues relevant to anxiety disorders in youth, 2) cognitive and affective neuroscience research and its applications to pediatric anxiety disorders, 3) fMRI study design and data analytic techniques, and 4) the ethical conduct of clinical research. Training will include: 1) formal coursework in cognitive neuroscience, fMRI, and ethics;2) mentoring;3) consultation with multidisciplinary experts;4) participation at scientific meetings;and 5) a research plan that complements career development activities. Research Plan: The proposed research aims to test the intolerance of uncertainty model of GAD, which postulates that GAD individuals are relatively unable to tolerate uncertainty, which leads to excessive worry and impairment. The first study will use a decision making task as a behavioral measure of intolerance of uncertainty in GAD adolescents and controls. Based on adult findings, it is hypothesized that compared to controls, GAD subjects will take significantly longer to make decisions under conditions of greater uncertainty. The second study will extend the intolerance of uncertainty model by using fMRI to test for differences between GAD adolescents and normal controls in neural activity during a decision making task. It is expected that compared to controls, GAD subjects will show significantly greater activation in paralimbic regions implicated in decision making and anxiety, during more uncertain conditions. Results will inform the candidate's future R01 application for further research linking this novel theoretical perspective on GAD to current neurocognitive approaches including those examining the role of emotion recognition and fear processing in pediatric anxiety disorders.